Latch mechanism and operating means therefor



June 14, 1938. w D 2,120,534

LATCH MECHANISM AND OPERATING MEANS THEREFOR Filed Dec. 24, 1937 INVENTOR GUN7/-/ER PH/L/P W/LD ATTORN EY Patented June 14-, 1933 EYE STAT ATENT OFFICE Gunther Philip Wild, Philadelphia,

to C. V. Hill & Company,

rd, assignor Incorporated, Trenton, N. 3., a corporaticn of New Jersey Applicaticn December 24, 1937, Serial No. 181,666 Claims. (Cl. 232-255) This invention relates to latches and operating mechanism therefor and particularly to constructions adapted for use on the doors of refrigerators, refrigerated display cases and else- Where.

The latches heretofore employed on refrigerator doors and the like to retain the doors in closed position have embodied a considerable A number of parts certain of which require lubrication from time to time. Furthermore, the spring means heretofore employed to project such latches have had to be moved through a considerable distance or placed under considerable tension when operated, with the result that when operated frequently the spring tends to lose its resiliency or to break due to fatigue or crystallization of the metal of which it is formed.

In accordance with the present invention these objections to constructions of the prior art are overcome by providing a novel type of latch operating means which requires no lubrication and is composed of a limited number of parts each of which is simple in construction. Moreover, the spring means employed for urging the latch into retaining position is moved through a very small arc and is so constructed that it will re tain its resiliency and resist breaking indefinitely.

The construction of the present invention is further characterized by the provision of means for limiting movement of the latch operating mechanism in retracting the latch whereby strain upon the elements is avoided even when the latch is operated by a foot treadle to which great force may be applied.

A further characteristic feature of the present invention resides in the use of a cam element for retracting the latch, the latch itself being of a cam type movable automatically into latch ing position on closing the door.

Among the important objects of the present invention are to provide novel latch operating means of a simple construction and embodying a limited number of parts, to avoid the necessity of lubricating the parts and to provide means which are capable of long continued operation under severe operating conditions without injury to the mechanism.

These and other features and objects of the invention will appear from the following descrip tion thereof in which reference is made to the accompanying figures of the drawing.

In the drawing:

Fig. 1 is a perspective of a typical form of latch and operating mechanism therefor embodying the present invention.

Fig. 2 is a horizontal sectional view of the construction illustrated in Fig. 1 taken on the line 2-2 thereof, and 5 Fig. 3 is a vertical sectional view of a portion of the construction illustrated in Fig. 2 taken on the line 3-3 thereof.

In that form of the invention illustrated in the figures-of the drawing a latch 2 is carried 10 by a door frame 4 or the like and movable into engagement with a keeper 6 on a door 1 or other member to be held in position by the latch. The latch 2 is formed with a bevelled surface 8 engageable by the keeper 8 to cam the latch in- 15 ward when the door is closed. The latch is urged outward into latching position by a spring it of suitable type so as to be projected behind the keeper when the door is fully closed. As shown, the spring preferably is in the form .of 20 a long strip of spring metal secured at its lower end to a bracket I2 set into a recess I4 in the door frame. The upper end of the strip vIt engages a stop pin IE on an upper plate l8 secured to the door frame and extending across 2 the upper portion of recess 14. For simplicity in construction the latch 2 is carried directly by the spring strip l0 and is secured thereto by riveting or other means in position to pass through an opening 20 in the upper plate l8. However, it will be evident that the latch may be supported in any other suitable manner to insure proper operation thereof.

The distance through which the latch 2 and the upper end of the strip 10 move in operating the latch are relatively small as compared to the distance between the latch and the bracket l 2 to which the lower end of the strip is secured. This distance of. course, will vary considerably in different constructions but it is desirable to 49 have the spring strip several times thelength of movement of the latch in order that the deflection of the spring strip will amount to only a very few degrees of an arc. With this construction the movement of the spring is so slight that it retains its resiliency indefinitely and is not subjected to the strain and fatigue to which such springs are usually subjected on repeated and long continued operation.

In actuating the latch to retract the same 50 against the action of the spring strip l0, operating means are employed which may be actuated by any suitable source of power. For purposes of illustration, a foot treadle 22 is shown, the treadle being carried by a lever 24 pivotally mounted on a pintle 26 supported by lugs 28 extending rearwardly from an escutcheon plate 30. The escutcheon plate is secured to the front of the refrigerator or other element by which the latch is carried and a slot 32 is formed therein within which the projecting portion of the lever 24 is movable. The projecting end of the lever carrying the foot treadle 22 is urged upward by the weighted inner end 34 of the lever 24, upward movement of the treadle being limited by a stop 38 carried by the treadle and engageable with the face of the escutcheon plate. A spring washer 38 is located between the supporting lugs and lever 24 about the pintle 26, so that these elements will not rattle or become loose on operation thereof.

The weighted inner end 34 of the lever 24 extends laterally from adjacent the pivot means to a point beneath an operating rod 40 which extends upward in the recess l4 adjacent the spring strip 10. The lower end of the rod 40 rests loosely in an enlarged recess 42 in the weighted inner end 34 of the lever and the recess is made deep enough to prevent displacement r or removal of the rod from the recess 42 in operating the device.

The upper end of rod 40 is threaded at 44 to receive nuts 48 adjustable to position the operating head or cam element 48 to insure proper operation of the mechanism. The head 48 is provided with a recess 58 into which the upper end of the rod 48 extends. A pin. 52 projects outwardly on either side of the head 48 to limit lateral movement of the head within the recess I4 while permitting free movement of the head vertically and in a direction parallel to that in which the latch is moved.

The upper end of the operating head 48 is inclined inwardly and upwardly to provide a sloping cam surface 54 movable into engagement with a fixed member or tongue 56 formed on the upper plate l8 and projecting rearwardly therefrom into the recess l4. At the lower edge of the cam surface 54 an abutment 58 is formed to limit upward movement of the head even when the foot treadle 22 is operated forcefully as would occur if the operator should stand thereon.

When moved upward by the operating rod 40 the cam surface 54 on the head 48 is brought into engagement with the fixed member 58 on plate 18. Thereafter on further upward movement of the operating rod the head is forced inward away from the plate l8 by the action of the fixed member and cam surface. The face 88 of the head is thus forced against the adjacent face of the spring strip I8 whereby the spring strip is forced to the right to the dotted line position of Fig. 3 and the latch 2 carried by the spring strip is thereby retracted. Lowering of the operating rod on release of the foot treadle allows the head 48 to fall and allows the latch to be again projected by the spring means employed. While jamming of the parts is prevented by engagement of the abutment 58 on the head with the fixed member 55 on the plate 18, the spring l8 serves to insure return of the head 48 to its lowered or inactive position, the spring serving to force the head forward and the cam surface 54 and fixed member 56 serving to force the head downward. Thus even though the operating rod is lowered more rapidly than the head 48 the return of the operating head to its lowered position and projection of the latch on release of the foot treadle is assured under all conditions of operation.

In the operation of, the latch on closing of the door the foot treadle and operating means are not actuated and remain in their normal inoperative position. The latch which initially is in its projected position, as shown in full lines in Fig. 3, is cammed inward by the keeper 6 on the door when the door is closed by engagement of the keeper with the inclined surface 8 on the latch. When the door is moved to its fully closed position and the keeper 6 passes beyond the latch, the latch is again projected by the spring means employed thus retaining the door in its closed position. This movement of the latch is independent of the operation of the latch operating means and therefore takes place freely and without danger of the parts sticking or being displaced so as to fail to operate properly.

In order to retract the latch so that the door may be opened, the actuating means, shown as a foot treadle, is operated whereby the weighted inner end 34 of the lever 24 is raised and the operating rod 48 is lifted forcing the head -48 upward. The head is cammed inward by engagement with the fixed member 58 so that it is forced against the spring strip In by which the latch is carried. The spring strip therefore yields and moves to the right as shown in Fig. 3 retracting the latch until it disengages the keeper so that the door is released for opening thereof.

Since the construction is intended for use over a period of years and when employed on refrigerators moisture may condense thereon, the parts and particularly the head 48 preferably are formed of stainless steel or other non-corroding metal or are subjected to rust proofing treatment before being installed. The simplicity of the construction and the limited number of parts employed render it unnecessary to lubricate the mechanism, particularly when the parts are formed of non-corroding material. Moreover, the spring means employed and the movement thereof through a very limited path serve to avoid fatigue or crystallization of the metal of which the spring member is formed, even though the latch is operated frequently.

The escutcheon plate 38 through which the lever 34 passes may be formed with a lug 82 projecting forward therefrom adjacent the lever 24 and beneath the foot treadle 22 to receive a padlock, the hasp of which may be passed through the opening 64 in the lug 62 to prevent unauthorized operation of the actuating means for the latch.

In the construction described herein and shown in the drawing the spring employed is in the form of a relatively long strip, however, it will be evident that other types of spring means may be employed either to replace or supplement the action of the spring strip Hi. It will also be apparent that the latch operating means may be actuated by hand or power means and that any suitable mechanism may be substituted for or used in conjunction with the foot treadle 22 to actuate the latch.

These and other modifications and changes may be made in the form and arrangement of the elements employed for operating the latch, particularly when adapting the invention for use in other types of devices than refrigerators and the doors therefor. In view thereof it should be understood that the form of the invention herein shown and described is intended to be illustrative of the invention and is not intended to limit the scope thereof.

'Iclaim; x 1. In a latch mechanism, a support, a latch"- movable with respect to said support into and out of a projected position, means for moving said latch to said projected position, a member fixed on said support, a cam element movable into engagement with said fixed member and said means and mechanism for actuating said cam element operable to move said cam element over said fixed member and against said means to retract said latch.

2. In a latch mechanism, a support, a latch movable with respect to said support into and out of a projected position, spring means for urging said latch toward said projected position, a member fixed on said support and projecting toward said spring means, a cam element movable into engagement with both said fixed member and said spring means and means for actuating said cam element to move the same over said fixed member and against said spring means to retract said latch.

3. In latch mechanism for a door, a latch supported on a door frame and movable into engagement with a keeper on said door, a spring strip operatively connected to said latch and serving to urge said latch into a projected position, said strip being located in a recess in said door frame and having one end thereof fixed with respect to said frame and the other end movable with respect thereto, a member fixed on said frame and projecting toward said spring strip near the free end thereof, a cam element movable between said fixed member and spring strip to retract said latch and means for actuating said cam element.

4. Door latching means and operating mechanism therefor comprising a keeper carried by a door, a latch mounted for movement toward and away from said keeper, yieldable means for urging said latch toward said keeper said latch having a cam surface engageable by said keeper on closing said door to retract the latch and allow the keeper to pass, and operating means engaging said yielding means to retract said latch including a cam member, movable into engagement with said yieldable means, a fixed member engageable by said cam member and means for moving said cam member relative to said fixed member and said movable means.

5. Latching mechanism for doors and the like comprising a latch mounted on a door frame and movable horizontally with respect thereto into and out of a projected position, a spring located in a vertically extending recess in said door frame for urging said latch toward its projected position and means for retracting said latch against the action of said spring including a member fixed on said frame and extending into said recess, a cam element located below said fixed member and movable vertically in engagement therewith, said element and member having cooperating surfaces inclined upwardly and inwardly serving to force said element inward on upward movement thereof, said element being operatively connected to said latch to retract the same on inward movement of said element and means in said recess for raising said element to retract said latch.

6. Latching mechanism for door and the like comprising a latch mounted on a door frame and movable horizontally with respect thereto into and out of a projected position, a spring located in a vertically extending recess in said door frame for urging said latch toward its projected position and means for retracting said latch against the action of said spring including a member fixed on said frame and extending into said recess, a cam element located below said fixedmem-ber and movable vertically in engagement therewith, said element and member having cooperating surfaces inclined upwardly and inwardly serving to force said element inward on upward movement thereof, said element being operatively connected to said latch to retract the same on inward move ment of said element, a rod movable vertically to raise said element to retract said latch and means for raising said rod.

'7. Latching mechanism for doors and the like comprising a latch mounted on a door frame and movable horizontally with respect thereto into and out of a projected position, a spring located in a vertically extending recess in said door frame for urging said latch toward its projected position and means for retracting said latch against the action of said spring including a member fixed on said frame and extending into said recess, a cam element located below said fixed member and movable vertically in engagement therewith, said element and member having cooperating surfaces inclined upwardly and inwardly serving to force said element inward on upward movement thereof, said element being operatively connected to said latch to retract the same on inward movement of said element, manually operable means for raising said rod and gravity actuated means for lowering the same.

8. Latching mechanism for doors and the like comprising a latch mounted on a frame for the door and movable horizontally into and out of a projected position, a relatively long spring strip located in a vertically extending recess in said door frame and having one end thereof operatively connected to said latch and having the other end secured in position with respect to said frame, said spring strip serving to urge said latch toward its projected position, a member fixed on said frame having a part projecting inwardly in said recess adjacent the free end of said spring strip, a cam element movable verticaly in engagement with the inwardly projecting part of said fixed member and positioned to engage said spring strip near the free end thereof to retract said latch on inward movement of said element, said cam element and part having cooperating surfaces serving to force said element inward on upward movement of said element.

9. Latching mechanism for doors and the like comprising a latch mounted on a frame for the door and movable horizontally into and out of a projected position, a relatively long spring strip located in a vertically extending recess in saiddoor frame and having one end thereof operatively connected to said latch and having the other end secured in position with respect to said frame, said spring strip serving to urge said latch toward its projected position, a member fixed on said frame having a part projecting inwardly in said recess adjacent the free end of said spring strip, a cam element movable vertically in engagement with the inwardly projecting part of said fixed member and positioned to engage said spring strip near the free end thereof to retract said latch on inward movement of said element and means for raising said element to retract said latch.

10. Latching mechanism for doors and the like comprising a latch mounted on a frame for the door and movable horizontally into and out of a near the free end thereof to retract said latch on inward movement of said element, said cam element and part having cooperating surfaces serving to force said element inward on upward movement of said element, a rod for raising said cam element, a lever for raising said rod pivotally mounted on said frame and weighted on its inner end to normally assume a lowered position and a foot treadle on the opposite end of said lever for raising said weighted inner end and said rod 10 to retract said latch.

GUNTHER PHILIP WILD. 

